Gaseous electric discharge device



Nov. 8, 1938. o. FRITZE 2,135,706

GASEOUS ELECTRIC DISCHARGE DEVICE Filed June 2, 1957 9 Fig. I.

INVENTOR Otiro Fritze A TORNEY conductofl whenthe switch'is'iii itsclosed circuit position, connectsthe heater eleme'nts of the'-electrodes'inwseries across the terminals of the current source forsaid .deviceand. short-circuits 20' thermostatic; switch ismountedexternal to container otthe; device andin-heat receiving relationtosomepart thereof, suchas the container trodes which Patented Nov. 8,1938 unit es ,0 gaseous elecaa m r P late' tofgas'ecus elecco prisintherlieatedf to a high discharge supporting temthe initiation of thegaseous therebetween. l V 1; abalic' twnai Number 642,8;32, iiled'November fl'6,l932, inventor Andrew H. "Young," a es-emselectricdischarge device of the above "type i disclose hi'ch compriseselecv nitially heated"to"an elevated temperatur'ebythe passage ofcurrent and a conductor' "comprising a thermostatic Switch which thedischarge'pathbetween the electrodes. The the wall adjacentone oftheelectrodes, so that when the electrode temperature risestO a value atwhich v the electrode is capable of supporting an arc discharge withoutappreciable disintegration the thermostatic switch moves to its opencircuit position and the discharge starts between the electrodes.

The object of the present invention is to provide a longlived gaseouselectric discharge device of the above type comprising a. thermostatprotected from the ambient without the need of protecting means externalto the lamp container and which thermostat is positive in operation.Still further objects and advantages attaching to the device and to itsuse and operation will be apparent to those skilled in the art from thefollowing particular description.

The invention attains its objects by enclosing the thermostatic switchin an hermetically sealed vessel and by mounting said vessel closelyadjacent one of the electrodes in the container of the gaseous electricdischarge device. The sealed vessel is either highly evacuated or isfilled with a gas, such as hydrogen, under substantial pressure tosuppress any arc between the contacts of the switch.

The thermostatic switch is intensely heated by the heat emanating fromthe electrode and is, therefore, positive in operation. When desired, aheat retaining element, such as a hollow metal cylinder open in thedirection of the discharge path, surrounds the electrode and thethermoan auxiliary starting circuit.

2,135,706 I GASiious ntactrmc mscmmca DEVICE Otto =Fritie, Berlin,Germany, assignor to Gen- 'erai-Electriocompany, a corporation of NewHeats; June 2, 1937, swarm). 146,047 Germany June 9, 1936 2'1Claims;(Cl. 176-124) static switch is mounted in the space between saidelectrode and said heat retaining element.

The thermostatic switch is provided with two current leads one of whichis connected to the heater element of the electrode adjacent the switchand the other of which is connected into The external part of thecurrent lead which is connected to the auxiliary circuit is coiledhelically and engages with a similarly coiled lead of the auxiliaryg cimcult. The mounting of the thermostatic switch in the container of thedevice is simplified by this structure since welding operations in closeproximity to vitreous parts of the lamp container or of the switchvessel are avoided.

In the drawing accompanying and forming part of this specification anembodiment of the invention is shown, in which Fig. 1 is a sideelevational, partly sectional view of one embodiment of the invention,and

Fig. 2 is a similar view showing in detail an end assembly of the deviceillustrated in Fig. 1.

Like numbers denote like parts in both the figures.

Referring to the drawing the gaseous electric discharge lamp devicecomprises an elongated, tubular container l having a gaseous atmospheretherein, such as rare gas at a pressure of about 1 to 10 mm., metalvapor, or a mixture of starting gas and metal vapor, which is luminosityproducing during the operation of the device. Thermionic activatedelectrodes 2 and 2' are mounted in the ends of said container I. Each ofsaid electrodes 2 and 2 consists of a rod of electron emitting material,such as barium oxide, and a heater filament, such as a tungsten filamentwrapped around said rod. Said electrodes 2 and 2 are surrounded by heatconserving shields 3 and 3', respectively, and said shields 3 and 3'having openings 4 and 4', respectively, therein in the direction of thedischarge path between electrodes 2 and 2'. The gaseous electricdischarge device is connected across the terminals 5 of a 220 v.alternating current source. A choke coil 6 is connected in series withsaid gaseous electric discharge device and a switch 1 is provided forconnecting and disconnecting said device across the terminals 5. Saidelectrode! is supported by a current lead 8 and the support 8" fusedinto the press ll of the stem of said container I and the electrode 2 issimilarly supported at the opposite end of the said container l. Theshields 3 and 3' are supported by a support wire attached thereto, as bywelding, which wire is fused into the press of said stems. The stem atone end of the container l is provided with the exhaust tube It.

The bimetallic switch it (shown in detail in Fig. 2) consists of anhermetically sealed vitreous container ll having a contact i2 and abimetallic strip I mounted therein. when said strip ll is suiflcientlyheated it moves from its contact making position to its contact breakingposition (indicated at I! in Fig. 2). The contact l2 of the switch isconnected by lead I! to the support wire 8" of the electrode 2 and thebimetallic strip ll of the switch is connected by lead I! to the currentlead 9. The external end of the current lead attached to the bimetallicstrip is is coiled helically (as shown at and is (as-- tened to the endof the current lead l5, which is similarly coiled, by screwing theseelements together during theassembly of the device. As shown in Fig. 1the current lead 9 is connected to the electrode 2' at the opposite endof the container I. When potential is first applied to the lamp deviceby closing switch I the bimetallic switch i0 is in a contact makingposition and current flows through the heater coils of the electrodes 2and 2', the bimetallic switch l0 and the conductor 9, short-circuitingthe discharge path between said electrodes 2 and 2. The how of currenttherethrough heats the electrodes 2 and 2' to an electron emitting, arcdischarge supporting temperature and the heat emitted bythe electrode 2heats the bimetallic switch II. In response to this heating the strip l4bends and moves to a contact breaking position. When contact is brokenin the switch It potential is impressed across the terminals of thedischarge device and a discharge starts between the electrodes 2 and 2.During the operation of the device the electrodes 2 and 2 are maintainedat an electron emitting discharge supporting temperature by the arcdischarge incident thereat and the bimetallic strip i4 is maintained inits contact breaking position by the heat emitted by said electrode 2.

While I have shown and described and have pointed out in the annexedclaims certain novel features of the invention, it will be understoodthat various omissions, substitutions and changes in the forms anddetails of the device illustrated and in its use and operation may bemade by those skilled in the art without departing irom the broad spiritand scope oi the invention, for example, when high frequency starting isdesired the bimetallic switch II is used to control the operation of thehigh frequency apparatus, when desired. or the bimetallic switch I. isused to control the operation of an auxiliary starting discharge in thedevice when that method of starting is used, and, when desired, thecurrent lead 2 is covered with an insulating material, such as glass,and is mounted inside of the container I.

What I claim as new and desire to secure by Letters Patent of the UnitedStates, is:

1 A gaseous electric discharge lamp device comprising a sealedcontainer, a gaseous atmosphere therein, electrodes sealed therein whichare.electron emitting when heated, a thermostatic switch mounted in saidcontainer and in heat receiving relation to one of said electrodes, aheat retaining means surrounding one of said electrodes and said switch,said switch consisting of a sealed vessel having a bimetallic strip anda contact therein, and an auxiliary starting means for said device, saidstarting means being controlled by said switch.

2. A gaseous electric discharge lamp device comprising a sealedcontainer, a gaseous atmosphere therein, electrodes sealed therein whichare electron emitting when heated, a thermostatic switch mounted in saidcontainer and in heat receiving relation to one of said electrodes, saidswitch consisting of a sealed vessel having a bimetallic strip and acontact therein, and an auxiliary starting means for said device, saidstarting means being controlled by said switch,

said switch having a helically coiled current lead engaging with asimilarly coiled lead of said starting means.

OTTO FRI'I'LE.

